Figure 2.

Simultaneous expression of more than one var promoter in transfected parasites. (A) Schematic map of the plasmid pVBH. (B) Levels of var gene expression detected by quantitative reverse transcription–PCR of complementary DNA obtained from transfected parasites. The columns show messenger RNA levels of each var gene in the parasite genome, the episomal bsd gene and three housekeeping control genes. RNA was extracted from a population in which one var gene (PFD1005c) was predominantly expressed above the others. Note that bsd is transcribed at a relatively high level, reflecting its expression from episomes by all parasites within the population.